湖南省桑植县油坊萤石矿床成矿地质条件

桑植县油坊萤石矿位于扬子准地台边缘,是一典型的小而富的低温热液充填型矿床。矿体主要由压扭性断裂控制,与围岩含Ca质有关,围岩界限清晰。矿体呈透镜脉状、似层状或扁豆状,矿石质量好,Ca F2含量高。该矿床广泛存在围岩蚀变作用,表现有硅化、绢云母化、黄铁矿化、碳酸盐化。该类型萤石矿床有明显的找矿标志。     

崩塌体水力输移与塌岸淤床交互影响试验

以二元结构河岸崩塌模式为研究背景,在弯道水槽中展开系列试验,研究凹岸坡脚处成型崩塌体在水力作用下输移过程及其对岸坡稳定性与河床冲淤的交互影响。试验成果表明,崩塌体经水力分解破碎呈块状、片状或颗粒状起动,部分随水流带至凸岸或下游,堆积在坡脚附近的崩塌体残留量随水力作用大小及土体特性不同而变化。崩塌体临水面周围尤其上下游端水流紊动强烈易形成较大剪切力区,临坡面上下游端附近剪切力较无崩塌体时减小;崩塌体体积越大,对剪切力区特征的改变也越明显。崩塌体的存在虽不能制止附近岸坡的再次崩塌,但可能抑制崩岸发展及附近河床淤积的程度,崩塌体的粘性或体积越大,这种抑制作用越显著;相同崩塌体抑制附近河床淤积的程度较抑制岸坡崩塌的程度大。     

试论胶东金成矿区成矿物质条件

对胶东群、粉子山群和蓬莱群的岩石学、地球化学等特征研究认为，胶东群是金的主要矿源层；粉子山群和煌斑岩脉也提供了部分金的来源。花岗质岩浆活动促使成矿物质转移。     

高陂区童子岩组沉积与聚煤特征

从野外第一手资料入手,分析了本区的童子岩组第三段中亚段的沉积特征。在此基础上,归纳出本区主采煤层沉积环境,并研究了主采煤层的聚煤特征。     

长江口深水航道治理工程综述

文章概要地介绍长江口深水航道治理工程的规划、勘察、设计和施工情况，对整治方案及主要岩土工程问题略作讨论。     

新疆煤层气资源赋存特征及开发潜力分析

通过对新疆主要煤田的煤炭资源分布特征，煤变质特征及构造特征分析，探讨新疆的煤层气资源赋存特征，对新疆主要煤田煤层气资源的勘探开发潜力进行初步评价，新疆的煤层气基本属于少生中储型，虽然单位含气量较低，但煤炭资源非常丰富，且相对集中，煤气具有较大的勘探开发潜力。     

舒兰煤田水曲柳区煤层气分布规律及利用方向浅析

舒兰煤田水曲柳区煤层气在平面上富气中心分布与富煤中心一致。该区煤层气属特低丰度、中等埋深的小型煤气田。适宜井下瓦斯抽采。可在建井后,在瓦斯富集部位煤层底板岩巷中,采用钻孔抽采方式,可回收近1.8亿m3煤层气,不但提高了资源的利用率,还将减少环境污染,提高了煤矿生产安全度,具有显著的经济意义和社会效益。     

冲击地压煤层大直径卸压孔快速成孔关键技术

为了提高冲击地压矿井大直径卸压钻孔的成孔率和施工效率,通过对冲击地压矿井煤岩体应力特征、卸压孔孔壁扰动动力失稳特性及施工特点的分析,探讨了大直径卸压孔快速施工的关键点在于高效排渣、快速成孔提钻。采用具有1.25 m行程轨道、大通孔动力头的ZDY4000LR型钻机,优化了大直径卸压钻孔施工操作流程,形成了水介质螺旋宽翼片双动力排渣高效成孔工艺方法,并在河南义马矿区和陕西彬长矿区进行了现场试验。结果表明：该工艺技术能够安全、高效地施工大直径卸压钻孔,施工效率较大螺旋钻进技术提高了48.9%,成孔率可达到100%。研究成果对类似冲击地压矿区施工煤层卸压孔提供借鉴。     

The red bed controversy revisited: shape analysis of Colorado Plateau units suggests long magnetization times

Several Triassic and earliest Jurassic sedimentary units from the Colorado Plateau region have distributions of virtual geomagnetic poles (VGPs) that are highly elongate along the path of apparent polar wander (APW). This suggests that the remanent magnetizations measured in these units were acquired over an extended period of time, possibly approaching 35 m.y., and are not precisely coeval with the stratigraphic age of the rock. Comparison with other paleomagnetic studies shows that the observed elongation is not a general attribute of the age of the rock, nor is it related to paleolatitude. The rocks that yield elongate VGP distributions are dominantly red to brown mudstones, and it is possible that their remanence is dominated by a slowly acquired chemical remanent magnetization, as suggested by Larson et al. [J. Geophys. Res. 87 (1982) 1081] and other authors. However, several superficially similar units from the Colorado Plateau have nearly circular VGP distributions. The process by which remanence is acquired in clastic sedimentary rocks merits further study.     

Correlation of Aptian-Albian sediments in the central part of North Caucasus and Ciscaucasia. Paper 2: Stratigraphy

A complex correlation between outcrops and well sections was performed for the central part of North Caucasus and Ciscaucasia using geophysical, biostratigraphic, and lithostratigraphic methods with new substage and zonal division of the Aptian and Albian sediments taken into account. Previously recognized local subsidiary stratigraphic units (members) were traced into the covered areas, and the stratigraphic position of productive layers was specified.